Method and apparatus for rolling metal strip



l 1940. L IVERSEN 2,198,009

IETHODAND APPARATUS FOR ROLLING METAL STRIP Filed Jan. 22, 1938 2Sheets-Sheet 1 34 35 32 a1 30 ALLA 8) I 6 6 INVENTOR Lorenzlvers 611.

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23, 1940. L. IVERSEN METHOD AND APPARATUS FOR ROLLING METAL STRIPFileciJan. 22, 1938 2 Sheets-Sheet 2 INVENTOR Lorenz IVersen QM PatentedApr. 23, 1940 METHOD AND APPARATUS FOR ROLLING METAL STRIP LorenzIversen, Pittsburgh, Pa., assignor to Mesta Machine Company, Pittsburgh,Pa., a corpora-' tion of Pennsylvania Application January 22, 1938,Serial No. 186,417

8 Claims.

This invention relates to the rolling of metal strip and particularly tothe hot rolling thereof.

Continuous hot strip mills of the design now in general use areeffective for turning out good quality strip in large quantity, buttheir initial cost is so high as to preclude their use in numerousinstances. By the present invention I provide a hot strip mill havinglow initial and operating costs and capable of turning out asatisfactory quantity of strip of high quality. The novel features of myinvention will best be appreciated by a consideration of the presentpreferred form thereof shown in the accompanying drawings.

In the drawings,

Figure 1 is a diagrammatic plan view of a strip mill embodying theinvention;

Figure 2 is a diagrammatic elevation thereof; and

Figures 3, 4 and 5 are diagrams to enlarged scale showing successivesteps in the operation of the mill.

Referring first to Figures 1 and 2, I have illustrated heating furnaces2 and 3 provided with pushers 4 whereby slabs of suitable size may bebrought up to rolling temperature and discharged as required onto a rolltable 5. The roll table 5 leads to an edging mill -6 having verticalrollers l driven by motors 8 through reducing gears 9. The rolls 1 areadapted to be adjusted toward and away from one another by a motor Hi.In the preferred form of my invention the motors 8 will be ordinarilyalternating current motors running in one direction only. Despite the 4strip mill is described in greater detail below.

The edger 6 is interposed between a section 5a of the roll table 5 and asection 5b thereof, the rolls of which sections are adapted to be drivenin either direction as desired by a motor ll. At the outer end of theroll table 5b there is a reducing mill l2 which is preferably of the4-high type having working rolls l3 and backing rolls M. The workingrolls are driven by a motor l5 through reducing gears l6. In thepreferred form of the invention I use an ordinary alternating currentmotor which operates constantly in one direction only, the work piecesbeing rolled from right to left as viewed in the drawings. The mill ispreferably provided with aflywheel (Cl. Bil-31.1)

ll, because by the use of such a flywheel the size of the motor may bereduced. The reducing mill I2 is provided with the customary screwdownmotor l8 whereby the working rolls l3 may be rapidly brought sumcientlyclosely together to engage and reduce a work piece or may be spreadapart so as to permit of the piece being fed through the millwithout-reduction.

Pushers l9 and 20 are provided on either side of the reducing mill l2and a turn table 2|, which may be raised or lowered soas to elevate apiece above the roll table 5b, is provided on the entering side of themill. As hereinafter explained in greater detail, the turn table 2| maybe used to turn a slab so that it will be presented broadside to thereducing mill l2. The pusher l9 serves to square the slab with the milland feed it between the working rolls I3. The pusher 20 is effective forengaging the rolled slab and returning it through the mill to theentering side.

Beyond the reducing mill l2 there is a roll table 22 whose rolls may bedriven in either direction by a motor 23. At the end of the roll table22 there are edging rolls 24 and a 4-high roughing stand 25. A rolltable 26 carries the piece from this stand to the edging rolls 2'! and a4-high roughing stand 28. A roll table 29 carries the piece from thisstand to a scale breaker 30 and thence through live sets of 4-highstands 3|, 32, 33, 34 and 35, constituting the finishing mill. Aflying shear 36 is provided at the delivery end of the mill and a runouttable 31 conveys the sheared pieces to a coiler or a piler as desired. t

The stands 24, 25, 21; 28, 30, 3|, 32, 33, 34, and 35 are alluni-directional and a piece once supplied to the rolls 24 continuesuninterruptedly through the mill. The treatment of the slab in thestands 6 and I2 will best be understood by reference to Figures 3, 4 and5, which show theseveral operations in sequence.

In Figure 3 a hot slab S as supplied from the heating furnace-is shown.This slab travels between the edging rolls 1 which serve to break the $5furnace scale and to square up the longitudinal edges. The slab sotreated is marked Si in Figure 3. The slab S1 is carried by the rolltable 5b to the turn table 2| which is thereupon elevated so as to clearthe slab of the table rolls, and is then turned through an angle ofapproximately 90 as shown in Figure 3. The pusher I9 is then loweredbehind the slab and advanced .toward the reducing mill l2. The head ofthe pusher l9 engages the slab along its edge, squares it with thereducing mill, and feeds it between the working rolls IS. The rolls willpreviously have been adjusted so as to effect a substantial reduction inthe thickness of the slab. At this stage of the operation the slab willbe of suflicient thickness that some lateral spreading will occur.Consequently the effect of this rolling step is to thin and widen theslab so that it is of the form indicated at $2 in Figure 3. The pusher20 is then lowered so as to engage the slab S2 and feed it back towardthe turn table 2|. The motor I8 is actuated so as to open the rolls l3and permit of feeding the slab between them. By reason of the positivefeeding action of the pusher 20 it is unnecessary to reverse the mill l2or to stop it.

After the pusher 20 has returned the slab S2 to the turn table 2|, theturn table is again rotated through 90 so as to align the longitudinalaxis of the slab with the axis AA of the mill. The slab is then loweredonto the roll table 5b, which is actuated in the reverse direction toreturn the slab to the entering side of the edging mill 6. The rolls 1will have been separated by the motor In so as to permit of free travelof the slab S2 therebetween.

After the slab S2 has been returned to the dotted line position ofFigure 5, the rolls 1 are brought closer together and the slab is fedbetween them so as to edge it for a second time. This brings it to theform 8:; of Figure 5. It is fed longitudinaly over the roll table 5b tothe reducing mill [2 and rolled longitudinally therein, the rolls f3having been brought closer together so as to effect the desiredreduction. This pass serves to thin and elongate the slab, bringing itto the form S4. It is now ready for treatment by the'subsequent standsin the strip mill for reduction to its final gauge.

The turn table and pushers will preferably be of the form shown in mycopending application Serial No. 31,433, filed July 11, 1935.

-By the use of my invention very material savings can be effected. Ascompared with usual installations, a universal mill stand and the tableand table mechanism accompanying it are eliminated. Certain otherelements usually employed, for example, the slab squeezer shown in myPatent 2,059,460, may be dispensed with. The electric motors andcontrols therefor are of relatively low cost yet will operate with fullsatisfaction. Despite these material savings in cost the mill willproduce high quality strip in satisfactory tonnage. In this connectionit should be borne in mind that the demands of the trade call for theproduction of strips of different widths. When rolling strips havingwidths which are not in excess of the slab width employed the mill iscapable of producing tonnages equivalent to the usual strip millinstallation and the tonnage is ony slightly reduced when a second passis made through the spreading stand in the manner above described. Thislimitation is offset by the reduced installation cost.

I have illustrated and described a present preferred embodiment of theinvention. It will be understood, however, that this is byway ofillustration only and that the invention may be otherwise embodied orpracticed within the scope of the following claims.

I claim:

1. In the method of rolling strip, thesteps consisting in feeding a slabbroadside through a .reducing mill, thereby widening and thinning it,opening the rolls of the reducing mill, returning the slab therebetweento the entering side of the mill while continuing to drive the rolls inthe original feeding direction, feeding the slab endwise through themill, thereby thinning and elongating it, and then reducing it to stripform by a series of endwise reducing passes.

2. In the method of rolling strip, the steps consisting in feeding aslab endwise through an edging mill, rotating the slab throughapproximately 90, continuing the feeding motion of the slab after suchrotation to a reducing mill, thereby to present it broadside to thereducing mill, passing the slab through the reducing mill, therebywidening and thinning it, opening the rolls of the reducing mill,returning the slab between the opened rolls to the entering side of themill while continuing to drive the rolls in the originel feedingdirection, rotating the slab through approximately 90 so that it ispositioned to travel lengthwise through the mill, passing the slablengthwise through the mill, thereby thinning and elongating it, andthen reducing it to strip form by a series of endwise reducing passes.

3. In the method of rolling strip, the steps consisting in feeding aslab endwise through an edging mill, rotating the slab throughapproximately 90, continuing the feeding motion of the slab after suchrotation to a reducing mill, thereby' to present it broadside to thereducing mill, squaring the slab with the mill, passing the slab throughthe reducing mill, thereby widening and thinning it, opening the rollsof the reducing mill, returning the slab between the opened rolls to theentering side of the mill, rotating the slab through approximately 90 sothat it is positioned to travel lengthwise through the mill, passing theslab lengthwise through the mill, thereby thinning and elongating it,and then reducing it to strip form by a series of endwise reducingpasses.

4. A strip mill comprising an edging stand having its rolls adjustablerelatively toward or away from one another to permit of an edging passor an idle pass therethrough, means for moving a slab endwise in eitherdirection between the rolls of the edging stand, a reducing stand havingits rolls adjustable relatively toward or away from one another topermit of a reducing pass or of an idle pass therethrough, and meansbetween the edging stand and the reducing stand for turning a slabwhereby it may be presented endwise or broadside to the reducing standafter traversing the edging stand.

5. A strip mill comprising an edging stand having its rolls adjustablerelatively toward or away from one another to permit of an edging passor of an idle pass therethrough, means for driving the rolls thereof ina non-reversing manner, means for feeding a slab endwise to the rolls ofthe edging stand so that it may be engaged thereby and fed between therolls to effect edging or for moving the slab between the rolls in theopposite direction when the rolls are sufiiciently'spaced apart, areducing stand having its rolls adjustable relatively toward or awayfrom one another to permit of a reducing pass or of 'an idle passtherethrough, means for driving the rolls of the reducing stand in anonreversing manner, and means for moving a slab in between the rolls ofthe reducing stand in a direction opposite that in which the slab is fedwhen engaged by said rolls.

r 6. Astrip mill comprising an edging stand having its rolls adjustablerelatively toward or away from one another to permit of an edging passor of an idle pass therethrough, means for driving the rolls thereof ina non-reversing manner,

means for feeding a slab endwise to the rolls of the edging stand sothat itmay be engaged thereby and fed between the rolls to efiect edgingor for moving the slab between the rolls in the opposite direction whenthe rolls are sufficiently spaced apart, a reducing stand having itsrolls adjustable relatively toward or away from one another to permit ofa reducing pass or of an idle pass therethrough, means for driving therolls of the reducing stand in a non-reversing manner, means for movinga, slab in either direction between the rolls of the reducing stand, andmeans between the edging stand and the reducing stand whereby it may bepresented endwise or broadside to the rolls of the reducing stand.

7. In a method of rolling strip, the steps consisting in truing theedges of a slab by feeding it endwise between edging rolls and' toward areducing mill, turning the slab 90 between the edging rolls and thereducingmill, feeding the edged slab broadside through the reducingmill,

thereby widening and thinning it, returning the slab to the enteringside of the reducing mill, turning it 90, and then feeding it endwisethrough the reducing mill, thereby thinning and elongating it.

8. In a method of rolling strip, the steps consisting in truing theedges of a slab by feeding it endwise through an edging mill and towarda reducing mill, turning the slab 90 between the edging mill and thereducing mill, feeding the edged slab broadside through the reducingmill, thereby widening and thinning it, returning the widened slab tothe entering side of the edging mill, again feeding the slab endwisetherethrough and edging it, feeding the widened and edged slab endwisethrough the reducing mill, thereby thinning and elongating it, and thenreducing it to strip formby a series of endwise reducing passes.

LORENZ IVERSEN'.'

